This invention relates to an optical recording sheet having information stored by optical recording dots, and a reproducing method and a recording apparatus for the recording sheet, and particularly relates to an optical recording sheet having optical recording dots arranged in a matrix shape, and a reproducing method and a reproducing apparatus for the recording sheet.
In the prior art, the reading of optical recording dots in a disc-shaped recording medium as represented by a compact disc (CD) and a video disc as disclosed in the Japanese magazine Electronics (published on May, 1983, pages 27-54) is carried out by providing a spiral groove in an optical disc and tracing the groove. That is, the tracking of a reading head is of mechanical type.
Further, in an optical card having optical recording dots arranged in a matrix shape, as disclosed, for example, in U.S. Pat. No. 4,634,850, an electrical tracking depending on data (ROM) read by an optical lines sensor is adopted as disclosed in Japanese laid-open patent publication JP-A-62-110628, or Nikkei Electronics (published on July 29, 1985, pages 99-101).
In the electrical tracking as mentioned above, it is difficult to recognize an address of arrangement of bits read by an optical sensor while the sensor is reading the address.
Further, when the arrangement of bits of data and the line sensor are inclined, there is a problem that a method of correcting the inclination is not sufficient and hence the accuracy of reading data is low.
Still further, there is another problem that a recording medium itself is expanded or diminished in size in an upward and downward direction or in a right and left direction and hence the accuracy of reading data is reduced.